@biskobe thanks for reaching out. I’ll address your questions below in-line.
You can promote all these handles under the same advertiser account and same funding instrument, but they need to be setup as promotable users first (a process by which the owner of that Twitter handle grants you permission to use them in promoted content).
There are two types of promotable users: FULL and RETWEET_ONLY. You can check the promotable users available to your advertiser account through GET accounts/:account_id/promotable_users and the docs for that endpoint explain a little bit about how promotable users work.
Adding promotable users is not a self-serve process. There is no UI for doing it and no API endpoint either. The process includes a step of grabbing legal consent from the owners of the Twitter handles you wish to add as promotable users and as a result it requires going through a human representative at Twitter.
The primary way of kicking off this process is to have the advertiser talk with their Twitter account manager. As an API consumer you’re a little blind to the process, but as soon as the process is completed you’ll see that the promotable users are available to you in GET accounts/:account_id/promotable_users.
If you’re working with an small-business (self-serve) advertiser account that doesn’t have access to their own Twitter account manager adding promotable users may not be an available option for you but you can use the “Help” link in ads.twitter.com to file a support ticket and request it.
Thanks for point out the dead link! I’ll get it fixed right away.
The correct link is: